Insecticide



Patented Feb. 3, 1925.

. No Drawing.

P711070: whom/it may: concemui-y Be it'known that-1,;Rumo 1G.1=ROAB 1 1,-a citizen of the United :StatesofAmcrica, and -resident of. Baltimore,- Baltimore city, State of Maryland, have invented certain mew and useful Improvements-in and Re- .l'ating to Insecticides, of'wh ich the followingis azspecification. r j' 1 I This inventionrelates toiarsenical insecticidesg and 'thexobjects and mature of the invention will be readily understood by those skilled in the art in the light of the following explanation of examples from among others Within the spirit and scope of my discovery and invention.

An object of the invention is to. produce an arsenical insecticide that will overcome certain disadvantages inherent in insecticides of .the arsenical class heretofore proposed, and that will not be destructive to growing vegetation yet willbe efiicient in the control of chewing insects that infest such vegetation.

l A great many arseniealcompounds have been used in the past for the control of chewing insects, but none has given entire satisfaction. Some of the compounds employed are the arsenates of lead, calcium, iron, zinc'and magnesium; thearsenites of calcium, zinc, copper and sodium; arsenic trioxide; arsenic disulfide and arsenic trisulfide. The arsenic compounds which are soluble in water, e. g., sodium arsenite, are

not used on vegetation because vegetation is injured by soluble arsenic. Even the relatively insoluble compounds of arsenic, such. as the arsenates of lead and calcium are sufiiciently soluble in water to prove injurious to delicate foliage such as the leaves of the peach tree. There is therefore a need for an arsenic compound. which is even less soluble in Water than lead or calcium arsenate and at the same time is sufficiently soluble in the stomach and intestinal juices of the insect to poison it when ingested.

-I have discovered that the arsenic com-' pounds known as arsenidc-sulphides.when finely powdered are poisonous to chewing insects and are not in'urious to the foliage of the peach tree. 1 y invention involves an insecticide the essential ingredient of which is formed by an arsenidc-sulphide.

I prefer to use the arsenide-sulphides occurring in nature, more especially the arsenide-sulphidesof iron, nickel and cobalt..

I NSEG TICIDE.

/ A ppl ieationx mam-A ust e,

. per cent metallic arsenic (As) as compared compounds are as fol1ows Tlhe formuleeand these 1 .w ro :.erswfie-snlnhidez A z-Fe zAs, f 6 %t k l-r rseai easu p id NiAs .Ni;S As,"l 5.24%, 1 ,Ceb l a sen esulph de' 1 Yo .CQAa-Q SiAs 4 -16%, .1 v

i These; compounds are gr jat-l y .super o a a en cal .co p mds iih re e r r as ins icides int-h t i y mi yts f b r oyed up n-t e m s d HQ te fi e-w t out. he add tion. of, hydrate 'i'liiu' I to the spray solution to reduce the soluble. arsenic. Furthermore, these arsenide-sul-' phides can be produced in finely powdered form ready for use as insecticides at very" much less cost than that'of the manufacture. of lead or. calcium arsenate, or any of the other arsenical insecticidesi The highprice 7.

of white arsenic in recent years has-. made" I the cost, of lead and 04110111111; arsenate so i great that their use has. been restricted. In

many instances, as in thecase of the cotton .30

grower, this has resulted in the loss of a large portion of the crop throu h failure to use any insecticide whatever. i lytinvention supplies arsenic in a formin which it" is poisonous to insects swallowing "it with;

their food; inwhich it is not injurious" to much less than other arsenical insecticides can be supplied for@ f g i V The preferred arsenide-sulphide"that, I employ is that of iron in its native stateiasi together with the rock orore with-which it is; associated, and the resulting powder used directly'as an insecticide, either as a dust or as a spray. H I These arsenide-sulphides contain'45 to 46 to 19.56% in standard lead arsenate and. I 26.08% in; calciumharsenate of the grade used in cotton dusting." It is thus seen that the same dosage of arsenic may hejobtained with a smaller quantity of arsenide sulphide than of'the commonly used arsenicals, lead and calcium arsenates. j 4

For uscas an insecticide an arsenide sulphide,for exan'iple iron arsenide-sulphide or arsenopyrite, is prepared by crush ng to i "Lo i were .1

a f themost delicate -\'egetatio11;'ja11d at a-prit'e ,l .j

the. mineral arsenopyrite. While I prefer H touse 'arsenopyrite in pure foitm, this is' i not essential to its successfulusefas an in I secticide. The'mineral may be pulverized a I: I

convenient size and then pulverizing in a Raymond, Fuller-Lehigh, or similar mill. I prefer'to use a powder of such fineness that not less'than 90% passes a 200 meshtest sieve. With-regard to thefineness. of the power, in general the finer the powder the quicker and more complete the insecticidal action. A powder which will just pass a 80 or 100 mesh sieve is efl'ective, but a powder which passes a 200 mesh sieve is very much more efi'ective. ''-It is very difficult to get a powder- 100% of which: will pass a 200-mesh sieve, but it is possible and practical to obtain one 90% ofwhich will pass a 200 mesh sieve, the other 10% being fine enough to pass a 100 mesh sieve.

The pulverized arsenopyrite may be employed exactly as other arsenical'insecticides.

be applied by dusting or' spraymay be mixedwith powdered sulhur-to form ad'usting' material, or it may lie mixed withBordeaux, nicotine solution, "etc, to form a combination spray. In all cases the dosage is based on the content of metallic arsenic ;(As), which percentage or content appears on the package or container or is otherwise made known to the user.

The pulverized arsenide-sulphides of nickel and cobalt, or' the ore or rock containing them may be prepared and used in an identical manner as that described for iron rarsenide-sulphide.

Vhat I claim-is:

1. An insecticide containing one or more of the arsenide-sulphides of metals of the iron groupreduced to a powdered form of a fineness suitable for dusting or spraying purposes.

2. An insecticide containing one or more of the arsenide sul hides of metals of the iron group reduce to a powdered form of a fineness'so that approximately 90 per cent will pass-through a substantially 100 mesh-test sieve.

RURIC .o. ROARK. 

